Revised Part L rules on residential energy efficiency for new homes in England have applied in full since June 20231. Solar Energy UK, the trade association, links the rules to a rise in solar installations on newbuild properties, and published figures on 10 March 2025 showing the share of new homes completed with solar panels1.
Solar Energy UK estimates that 45,070 newbuild homes were completed in England in the fourth quarter of 2024, the latest period for which figures were available, while Microgeneration Certification Scheme (MCS) data record 18,954 installations on newbuild properties over the same period1. Assuming all of those were on homes indicates that 42% of these new homes are solar-powered, the association said1. That compares with 5,731 of 44,310 newbuilds, or 13%, in the last quarter of 20231.
The reported quarterly progression was 13% in Q4 2023, 16% in Q1 2024, 18% in Q2 2024, 32% in Q3 2024 and 42% in Q4 20241.
| Quarter | Share of newbuilds with solar |
|---|---|
| Q4 2023 | 13% |
| Q1 2024 | 16% |
| Q2 2024 | 18% |
| Q3 2024 | 32% |
| Q4 2024 | 42% |
Source: Solar Energy UK1
Chris Hewett, Chief Executive of Solar Energy UK, said:
"It's a reasonable assumption that at least 40% of new English homes now have solar power, given the clear trend in the data. It will certainly be a much higher proportion by the end of the year, when the transition to an upgraded energy efficiency requirement under the Building Regulations should be complete. Comparable rules in Scotland led to 80% of new homes having panels fitted"
The association also reported that the average capacity of systems fitted to newbuilds has fallen, from about four kilowatts at the end of 2023 to 2.4kW in the fourth quarter of 20241. Stuart Elmes, Chief Executive of Viridian Solar, attributed the change to a shift from site-wide planning conditions and self-build specifications towards installations by private developers1. A typical residential installation is around 4kW, according to the association1.
On existing homes, Solar Energy UK said the number of solar retrofits in England has hovered around 8,000 to 10,000 each month for more than a year1. It put the number of rooftops with smaller-scale solar installations across the UK at over 1.6m, with more than 180,000 added in 2024 alone; for England the figure stands at 1.3m, of which 169,000 have come since January 20241. MCS-scale installations are those below 50 kilowatts of capacity, most of which are mounted on home roofs1.
The figures cover MCS-registered installations, which include some on new non-domestic properties, and exclude some installations of appropriate scale that are not registered with MCS; Solar Energy UK said the two factors are likely to roughly cancel each other out1. Home building activity in the fourth quarter of 2024 was estimated from National House Building Council statistics, with earlier figures from the Office for National Statistics1.
Why it matters for households
For a household buying a new home in England, the figures suggest a solar array is now a common rather than occasional feature of the specification, and that the Building Regulations in England route, rather than local planning conditions, is the main driver1. The reported fall in average newbuild system capacity, from about four kilowatts to 2.4kW, means the typical array on a newer home is smaller than those fitted a year earlier, which affects how much of a home's electricity a roof can be expected to cover1. The association's comparison with Scotland, where it says comparable rules led to 80% of new homes having panels fitted, indicates the English share could rise further1. For existing homes, the retrofit rate of roughly 8,000 to 10,000 a month in England indicates that most homes remain without solar1. What buyers are entitled to under new build homes and energy rules, and how installations are certified under MCS, are separate from the Part L requirements themselves.
What happens next
Solar Energy UK said it expects the transition to an upgraded energy efficiency requirement under the Building Regulations to be complete by the end of 20251. It also said it expects the Future Homes Standard to all but mandate substantial solar installations on new homes1. No commencement date for that standard is given in the figures published on 10 March 20251.